(Sports Network) - The Pittsburgh Pirates' pitching staff has the worst earned run average in the National League. Perhaps adding another arm will help.

Ross Ohlendorf will join the Pirates' now six-man rotation tonight, when he makes his first major league start in the second test of a three-game series versus the Cincinnati Reds at Great American Ball Park.

Ohlendorf was acquired from the Yankees in late July in the deal that sent outfielder Xavier Nady and reliever Damaso Marte to the Bronx. Ohlendorf, a September callup, becomes the second player from that deal to be added to Pittsburgh's rotation, joining Jeff Karstens.

The right-handed Ohlendorf made 25 relief outings with the Yankees prior to the trade, going 1-1 with a 6.53 ERA. The 26-year-old went 4-3 with a 3.47 ERA in seven starts with Pittsburgh's Triple-A club.

Ohlendorf actually faced the Reds while with New York on June 21, allowing two hits in two-thirds of an inning.

The Pirates, who are last in the NL with a 5.20 team ERA, had lost a season- high 10 straight heading into Tuesday's opener and appeared to be heading towards yet another setback when the Reds' Chris Dickerson began the bottom of the first with a home run.

However, Brandon Moss and Andy LaRoche, two players acquired in the three-team deal that sent former Pirate Jason Bay to Boston, hit back-to-back solo homers in the second.

The Reds then tied it in the bottom of the frame, but Nate McLouth's ground out that scored pitcher Ian Snell in the third proved to be the difference in the Pirates' 3-2 victory, their first since August 19.

Snell threw six innings in getting the win, while Moss had three hits and is batting .366 (15-for-41) with four homers and six RBI in his last 11 games.

Corey Patterson singled home Jay Bruce in the second, but the Reds offense failed from that point on to halt Cincinnati's three-game win streak.

Edinson Volquez starts for the Reds aiming for a fourth straight winning decision. The righty won his third straight on Friday despite allowing six runs on eight hits over 5 1/3 innings versus the Giants.

Volquez posted a 3-1 record in each of the last two months despite an ERA of 4.54 in July and 4.50 in August. He is 16-5 on the season with a 3.04 ERA, the first time all year that number has gone above three.

The 25-year-old righty is 1-0 with a 2.12 ERA in three starts against the Pirates -- all coming this season. He picked up the lone win on August 12 with 6 2/3 innings of one-run ball.

Pittsburgh has won eight of 13 versus Cincinnati this year.